Flat Roofing 101

Flat roofs are increasingly popular for their clean look and easy maintenance. Their level surface and clean lines make them wholly contemporary in style. Truth be told, though, flat roofs are not entirely flat. Rather, they feature a slight slope, known as a pitch, to prevent the accumulation of rainwater. Flat roofs are durable enough to last decades, which is why they have not only created a buzz among homeowners but also real estate agents and commercial builders.

Are you mulling on flat roof installation for your home? If so, then you should find out everything you can, including its different iterations, benefits, and tips for maintenance, before installing one. To discover them, keep reading this blog post!

Flat roofing construction


Different Types of Flat Roofing

There is no single type of flat roof. In fact, there is a wide variety based on different roofing systems.

1. Built-up Roof (BUR)

Built-up roofs are made from hot tar and gravel, and feature three or more layers of waterproof ply sheets inserted between the layers of tar. Smooth river stones or gravel is used to cover the first layer to make it durable and stable. (Gravel, by the way, is flame retardant, making this type of roof less susceptible to fire than others.) However, built-up roofs are heavier than others due to their multiple layers. This can affect the building’s structure and incur high replacement costs.

2. PVC Membrane

PVC membranes are highly reflective, lightweight, and recyclable, as well as chemical and flame resistant. They are constructed from a continuous filament lattice, commonly known as a scrim. UV resistant thermoplastics, with variants like Thermoplastic Elastomers (TPE), Polyisobutylene (PIB), and Thermoplastic Polyolefin (TPO), are used to laminate the first layer. This roof type is flexible and can be easily customized but requires expert installation.

3. Modified Bitumen

Modified bitumen features two or three layers of bitumen sheets applied with the use of a gas torch. It is light in colour, thus reflecting sunlight and reducing electricity bills by decreasing air conditioning needs. As its application requires use of a torch, however, installation can be hazardous, which is why this type of roof should be avoided in occupied buildings. Safety precautions should be taken prior to installation, including making sure materials are protected from the elements before installation.

4. Rubber Membrane

EPDM (ethylene propylene diene terpolymer) or rubber membrane roofs are durable, coloured black, and easily repaired. They are hardier than other older flat roof systems, like BUR and modified bitumen, but absorb more heat due to their natural black colour. This increases electricity bills due to an increased need for air conditioning. However, this cost can be mitigated by installing light-coloured roof coatings. This makes installation costlier but will save you money long term.

5. Thermoplastic Membrane (TPO)

Thermoplastic membrane, or TPO (thermoplastic polyolefins), is white in colour and similar to PVC roofing materials. It is made from polypropylene and ethyl propylene rubbers, and features a flat, single-ply membrane. Due to its natural white shade, it reflects sun, thus reducing your AC bill. In addition, this roof type is durable and flexible enough to take any shape.

Advantages of Flat Roofing

There are many advantages to installing a flat roof:


Whenever you look at a house or building with a flat roof, what do you notice first? Its clean, clutter-free design which makes it a stand-out choice.

Low Maintenance

Detecting problems in flat roofs is a lot easier compared to sloped ones. Cleaning its gutters is also comparatively easier, but be sure to keep them clean in order to prevent clogging by water after heavy downpours. Many people select this roof type for their homes or commercial buildings because it can last years with little maintenance.


Fewer materials are used in building flat roofs than others. Installation times are also shorter, with smaller buildings only requiring a day or two.


The average flat roof can last for more than 30 years if you keep it in good shape.

Handy Maintenance Tips

Here are a few maintenance tips that can come in handy if you’re selecting a flat roof:

  • Inspect it monthly or hire a professional to do so. Fix damage as soon as it occurs to prevent it from getting worse and thus more expensive to repair.
  • Use a protective paint to reflect damaging ultraviolet rays. This paint can also lubricate the roof and reseal its surface against water.
  • Keep it clean, especially after heavy rains. This way you prevent clogging.
  • Make sure you have a good drainage system to ensure your roof’s longevity.

Important Things to Know About Flat Roofs

There are a few more things that you should know about this roof type.

  • Though flat means level, flat roofs are actually slightly sloped.
  • Flat roofs are easy to renovate.
  • There is a wide variety of flat roofs available. Choose yours based on your budget and other requirements.
  • Flat roofing requires the installation of gutters to ensure good drainage.


In a nutshell, flat roofs are durable, cost effective, aesthetically appealing, and hassle-free compared to traditional roof types. The installation of a modified bitumen roof can be hazardous as it requires use of a gas torch, but with proper precautions, this is no problem at all. Hence, if you’re looking for a roof that is fancy, sturdy and low maintenance, a flat roof is the right choice for you.

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